MFI engine hesitation when speed switch/RPM transducer connected

[SFE]

You have no high tension lead to the distributor???

On the distributor I have a black wire coming from the CDI and the black/violet going to the tachometer.


Here is my coil, I have removed the wire (red arrow) because it was the white/red wire supposed to go to the ballast unit.

[edmayo]

You confused me, in the post above you said "no black wire between the coil and distributor" then you edited Tom's drawing showing the removed high tension lead. I guess that isn't what you meant.

[SFE]

You confused me, in the post above you said "no black wire between the coil and distributor" then you edited Tom's drawing showing the removed high tension lead. I guess that isn't what you meant.

Not sure to understand what is the « high tension lead ».
The thing is I don’t see any black wire between the coil and the distributor, that’s why I’ve removed it from Tom’s drawing.

[edmayo]

The high tension lead is the cable that runs from the center of the ignition coil to the center of the distributor cap. It carries the high voltage which goes to the rotor and then eventually to each spark plug in turn.

[tom1394racing]

The high tension lead is the cable that runs from the center of the ignition coil to the center of the distributor cap. It carries the high voltage which goes to the rotor and then eventually to each spark plug in turn.

SFE....The high tension lead shows in your photos. The car would not run without it. It might be helpful to try the MFI transducer diagnostics and report back with your findings.

[SFE]

SFE....The high tension lead shows in your photos. The car would not run without it. It might be helpful to try the MFI transducer diagnostics and report back with your findings.

Yes I will.

So you find nothing wrong or missing in my wiring ?

[SFE]

Hi All,

some video of what happen when the RPM transducer is depressed (as it should be at idle)....the solenoid is energized for some reason !!!?

https://youtube.com/shorts/lgupWjk-Fgo

https://youtube.com/shorts/iFa40lKbKf0

[tom1394racing]

What happens when you press the micro switch at 3000 RPM? The engine should shut down.

[SFE]

What happens when you press the micro switch at 3000 RPM? The engine should shut down.

I did that test around 2000/2500 and rpm drop to around 1300 then rises back to around 1600….and again and again.
So I think the transducer is working as it should be upon decel.

Never did that test at 3000…

[edmayo]

Your video seems to show two wires going to the shut off solenoid, there should only a red wire.